This invention relates to the field of surgery and more particularly to a tool useful for performing anastomoses and having a locking mechanism.
The term "anastomosis" covers a variety of procedures in which blood vessels or other tubular members, such as parts of the colon, are joined or reconnected. Vessels may be joined in a variety of relative orientations, including end-to-end and end-to-side. Solid tubular structures such as peripheral nerves can also be joined together, as well as solid structures such as subcutaneous tissue and skin.
Anastomoses are traditionally performed by joining, clipping or suturing the vessels together at the juncture between them. Alternatives to suturing have been developed, in order to prevent thrombosis which tends to occur at the points of penetration of the sutures. One such alternative, particularly for larger vessels, involves mechanical connectors such as collars. A second alternative to suturing is the use of surgical dips which are applied along the vessel juncture to perform a holding function similar to that of sutures, without penetrating the vessel walls. Two such non-penetrating clips are shown in U.S. Pat. Nos. 4,586,503 and 4,733,660 to Kirsch et al. As described in the former patent, the non-penetrating clips are applied over apposed edges of the vessels, the edges first being everted, or turned outward, to form flanges that are gripped between the jaws of the clips. Eversion not only enables the clip jaws to better grip the vessels, but also insures that only the interior surfaces of the vessels are in contact.
The use of such non-penetrating clips requires that the vessel or tissue edges be accurately and symmetrically everted. Correct eversion is critical at the beginning of anastomoses and at difficult sites, such as at the heel and toe of an end-to-side anastomosis.
For an astomosis, a blood vessel is everted by rotating the exposed end of the vessel such that the vessel's intima is exposed and is transverse to the longitudinal axis of the vessel. During anastomosis, this part of the vessel end must be everted and held in close relationship while the final steps of joining the blood vessels are performed. The fact that surgical clips have proven fast, simple to apply and reliable in their holding ability, has accentuated the need for a tool to assist a surgeon in everting vessels while performing anastomoses.
Clips are typically applied with a small hand-held tool that enables the surgeon to precisely place the clip over the tissue edges, and then to close the dip, as by applying a squeezing pressure to the tool. It is desirable to enable the same surgeon to perform the required vessel eversion, with his free hand.
One example of a prior art everting forcep is disclosed in U.S. Pat. No. 4,950,281 to Kirsch et al., the contents of which are hereby incorporated by reference, where the forceps include a pair of outer legs and an inner leg all cooperating jaws are mounted at the ends of the respective relatively movable legs. The outer legs can be independently manipulated to evert a vessel for anastomosis procedure.
It would be desirable to provide a mechanism in the everting forceps which could lock one of the legs during manipulation of the other leg. This would advantageously allow the surgeon to release his grip on the locked legs to evert the other vessel with the unlocked leg. The forceps is used by grabbing the vessel between one outer leg and the intermediate leg and everting the vessel. The user maintains pressure on these two legs while the opposing vessel is grabbed and everted by the second free outer leg in cooperation with the intermediate leg.